Lubricator for percussive tools



1933. L. L. RICHARDSON 1,923,797

LUBRICATOR FOR PERCUSSIVE TOOLS Filed March 11, 1929 Patented Aug. 22,1933 UNITED STATES PATENT OFFICE LUBRICATOR FOR PERCUSSIVE TOOLSApplication March 11, 1929. Serial No. 346,077

2 Claims.

The present invention is directed to improvements in lubricators forpercussive tools.

The primary object of the invention is to provide a device of thischaracter so constructed that the lubricant will be automaticallyconducted to the working parts of the tool, regardless of the positionof the tool; and further to so construct the device that vibration andair pressure will in no way interfere with the operation thereof.

Another object of the invention is to provide a device of this kindconstructed in such manner that the flow of lubricant will be constant.

Another object of the invention is to provide a lubricator of this typewhere small ports and passages are eliminated in order to preventclogging by grit or other foreign matter.

With these and other objects in view, this invention resides in thenovel features of construction, formation, combination and arrangementof parts to be hereinafter more fully described, claimed, andillustrated in the accompanying drawing, in which:

Fig. 1 is a cross-sectional view of the back head of a percussionreservoir therein; and Fig. 2 is a cross-sectional view showing the oilpassage from the reservoir to the operating parts of the tool on anenlarged scale.

Referring to the drawing, 1 designates the backhead of the tool, and inwhich is formed a reservoir 2 for containing a copious supply of oil.The reservoir is replenished with oil through the opening 3, saidopening being normally closed by the screw plug 4.

A plate 5 constitutes bottom of the reservoir 2, said plate beingpressed into the reservoir and has formed in its under surface a recess6 to accommodate the upper end of the rifle bar 7, said bar havingassociated therewith the usual ratchet mechanism 8.

The head 1 and the ratchet mechanism are mounted upon the cylinder 17which is of conventional construction well known in the art. A piston(not shown) is arranged to reciprocate in the cylinder 17 under theinfluence of motive fluid conducted thereto by suitable valve andpassages. The valve construction together with the passages forconducting fluid to both ends of the cylinder and the pistonconstruction are all well known in the art and it is not deemednecessary for a complete disclosure of this invention to do more than torefer to the art such as is illustrated by Patent No. 1,809,284 for adisclosure of such valve and passages for operating a piston. It isinherent in the operation of a pneumatic tool of this type that, in thespace above the piston in and about the ratchet mechanism the pressurewill fluctuate widely throughout a cycle of operation.

A boss 9 extends upwardly from the bottom 5 and into the reservoir, andin which is formed an eccentrically located threaded opening 10 adaptedto receive the screw plug 11, said plug serving as a closure for theupper end of the chamber 12 which extends partly into the plate 5 5 andboss 9.

The upper end of the chamber 12 communicates with the reservoir throughthe horizontally disposed port 13, while the lower end thereofcommunicates with the recess 6 through the V inclined passage 14.Obviously, oil admitted to the chamber 12 through the port 13 will flowfrom the passage 14 to lubricate the ratchet mechanism 8 and from thencethrough the opening 15 of the rifle bar guide plate, 16 mounted ascustomary in the upper'end of the cylinder 17, and in which the hammer,not shown, reciprocates.

A ball 18 is retained in the chamber 12 by the plug 11, the diameter ofthe ball beingsslightly less than that of the chamber so that while oilcan flow at all times past the ball, the flow thereof will be retardedby the ball to prevent a too rapid flow of oil from the passage 14 intothe tool.

Since the plug 11, constitutes the top of the chamber 12, and the bottomof the chamber is disposed on an angle of to the tile wall thereof, theball cannot at any time t'nse the port 13 and passage 14, thus permittimoil totv 90 enter and leave the chamber.

The oil reservoir being in the motive fluid line a pressurecorresponding to that in the fluid line will be built up in saidreservoir. When motive fluid is admitted to move the piston the;pressure in the line will be momentarily reduced, thus causing oil toflow from said reservoir to the operating parts of the tool. When themotive fluid is cut off from the piston the pressure in the line will bemomentarily builtZLlOO up to normal again and the flow of oil will beretarded or momentarily stopped due to this increased pressure. Theintermittent feeding of the oil through the restricted passage and thevibration of the tool will cause movement of the-T10 ball 18 within thechamber 12.

As before pointed out fluctuating pressure about the ratchet mechanismis inherent in pneumatic tools of the type to which this inventionrelates. The recess in the boss 9 is in fluid communication with thehead of the cylinder and therefore is subjected to such fluctuations inpressure. When the pressure is increased motive fluid passes through theorifice 14 into the chamber 12 and about the ball 18, there being a fewthousands of an inch clearance about the ball, from passage 12 throughthe aperture 13 and into the reservoir 2. Thus a high pressure is builtup within the reservoir 2 which tends to force lubricant out of thatreservoir through the passages l2, l3 and 14. Due to the small clearancebetween .the ball 18 and the walls of the passage 12, 'it Will'be movedupwardly during the passage :of motive rfluid from the cylinder into the"reservoir '2. -As the cycle of operation of the pneumatic toolcontinues the pressure within the top of :the cylinder, and at theorifice 14 will be reduced below that existing in the reservoir 2 sothat oil will be forced out of the reservoir 2 through aperture 13 ofpassage "12 and orifice "14 "into the cylinder'2 which will lubricatetheratchet mechanism aswell as the piston and associated 'moving parts. Theball 18 by'virtue of its relatively small spacing from the walls ofthepassage 12 acts to regulate the flow of lubricant through the passage'12. By providing such a construction aipassage "12 may be providedwhich is not subject to clogging -by debris in the lubricant. Thespacing between the walls of -the passage Y12 and the ball 18 is keptclear and free :from "clogging by the movement of the ball 18under theinfluence of motive fluid passing from the cylinder'to the reservoir 12,under the influence of lubricant passing from the reservoir 2 into thecylinder and also under the influence of vibration of the tool of theoperation. Thus a practical, easily manufactured, form of .automaticmeans for supplying lubricant to the "tool 1 which is so constructed asto be free from clogging and to automatically clear itself from debris"in those operations has been provided.

chamber between the reservoir and the interior of the .tool, saidchamber having a port opening into its upper end for conductinglubricant from'the :r'eservoir to the chamber, and having a passageleading from the lower end 01 the chamber to the interior of the toolfor conducting lubricant ;from the chamber to the working parts of thetool, a ball mounted within the said chamber and freely movable thereinfor restricting the flow of lubricant through and from the chamber, thesaid passage and said port being disposed remote the surface of the ballto assure continuous 'fluid passage from the reservoir :to the interiorof the tool.

chamber between the reservoir and the interior of said tool, saidchamber having a port adja- '2. The combination with a fluid actuatedtool" having an oil containing reservoir therein, of a cent theupper'end wall of said chamber for.

conducting lubricant from the reservoir to the chamber and having apassage adjacent its lower end Wall for conducting lubricant from thechamber to the working parts of the tool,

a member mounted Within said chamber and completely reciprocable thereinfor restricting the flow of lubricant through and from the chamber, saidpassage and said port being .dis-

posed remote said member and free from obstruction by said member toassure the continuous 'fluidpassage from the reservoir to the interiorof said tool.

LED L. RICHARDSON.

